To assess safety and efficacy of pCONUS2 for the treatment of wide neck bifurcation aneurysms.

Title: pCONUS2 Treatment of Wide Neck Intracranial Aneurysms 2

Acronym: pToWin2

Device: pCONUS2 Bifurcation Aneurysm Implant

Study design: Prospective, multicenter, single-arm clinical investigation

Purpose: To assess safety and efficacy of pCONUS2 for the treatment of wide neck bifurcation aneurysms

Duration of the study: 30 months

Sample size: 100 evaluable patients

Number of sites: max. 15

Follow-up intervals: Two independent follow-ups (after 3-6 and 7-12 months) according to site specific standard

Inclusion Criteria:

1. Aneurysm status:

   • Unruptured aneurysm or
   • Ruptured aneurysm with a Hunt and Hess grade of I - III.

2. Age ≥18.

3. The patient or legal representative provides written informed consent.

4. The patient shows general compliance to follow the medical regimen and to attend follow-up examinations.

5. The target aneurysm is located at one of the following cerebral vessel bifurcations: ICA terminus, AcomA, MCA or BA.

6. Bifurcation wide neck aneurysm.

7. The dome height should allow for safe deployment of the device crown. The fundus of the aneurysm should offer enough space for the crown of the pCONUS2 to deploy.

Exclusion Criteria:

1. Vessel tortuosity precluding safe access and device deployment.

2. Stenosis within the vascular access or target vessel ≥ 50 %.

3. The target aneurysm has been previously treated with a stent or an intraaneurysmal implant beside coils.

4. The treatment plan for the target aneurysm includes the use of additional intra- and/or extraaneurysmal temporary or permanent implants other than coils.

5. More than one intracerebral aneurysm requires the treatment within the following 6 months.

6. Imaging evidence of an arteriovenous cerebrovascular malformation or a dural fistula.

7. Any physical, medical or psychiatric condition of the patient interfering with the adherence of the requirements and follow-up regimen of the study.

8. Any neurological disorder with progressive neurological symptoms, except attributable to a compressive effect of the target aneurysm.

9. Current involvement in another study or trial.

10. Women of child bearing potential or breast-feeding who cannot provide a negative pregnancy test.

11. Known allergy to the components of device, study medication or contrast media that cannot be controlled medically.

12. A medical condition interfering with a dual antiplatelet treatment.

13. Known coagulopathy.

14. Intracranial hemorrhage in the past 30 days apart from the target aneurysm.

15. Ischemic stroke in the past 30 days.

16. Myocardial infarction in the past 30 days.

17. Major surgery in the past 30 days.

18. Evidence of active infection at time of treatment.

19. Co -morbidities or conditions with a life expectancy less than 12 months.

20. Additional Exclusion criteria for ruptured aneurysm at the acute phase:

    1. The patient is clinically severely affected (Hunt and Hess grade IV and V).
    2. Severe vasospasm is proven during angiography.
    3. Proven parenchymal hemorrhage by CT or MRI.
    4. Proven subdural hematoma by CT or MRI.

Patients harbouring an unruptured or ruptured bifurcation aneurysm, in which pCONUS2-assisted coiling was judged to be the most appropriate treatment